Earphone having pressure equilibrium structure

Abstract

Provided is an earphone having a pressure equilibrium structure capable of preventing a decrease in acoustic characteristics or sound pressure, while having a structure capable of achieving equilibrium within an ear canal. The earphone includes a receiver including a frame, a magnetic circuit, a voice coil, and a diaphragm, a front housing surrounding a front and a side surface of the receiver and including a sound tube, a rear housing attached to a rear of the receiver and coupled to the front housing, and a duct located between the diaphragm and the sound tube. An acoustic path through which sound is emitted is formed from the receiver to an end of the sound tube. The front housing or the rear housing includes a leakage hole. An inner end of the duct is connected to the acoustic path. An outer end of the duct is connected to the leakage hole.

What is claimed is: 
     
       1. An earphone having a pressure equilibrium structure, the earphone comprising:
 a receiver including a frame, a magnetic circuit, a voice coil, and a diaphragm; 
 a front housing surrounding a front and a side surface of the receiver and including a sound tube; 
 a rear housing attached to a rear of the receiver and coupled to the front housing; and 
 a duct located between the diaphragm and the sound tube, 
 wherein an acoustic path through which sound is emitted is formed from the receiver to an end of the sound tube, the front housing or the rear housing includes a leakage hole, an inner end of the duct is connected to the acoustic path, and an outer end of the duct is connected to the leakage hole, 
 wherein the receiver further includes a protector coupled to the frame of the receiver to protect the diaphragm and disposed to be in contact with the front housing, 
 wherein the duct is formed by a groove located on a front surface of the protector in contact with the front housing. 
 
     
     
       2. The earphone of  claim 1 , wherein the leakage hole penetrates a front surface or the rear surface of the front housing. 
     
     
       3. The earphone of  claim 1 , wherein:
 the leakage hole is formed in the rear housing; and 
 the protector includes a connection path formed by the groove on an outer surface and connected to the duct. 
 
     
     
       4. An earphone having a pressure equilibrium structure, the earphone comprising:
 a receiver including a frame, a magnetic circuit, a voice coil, and a diaphragm; 
 a front housing surrounding a front and a side surface of the receiver and including a sound tube; 
 a rear housing attached to a rear of the receiver and coupled to the front housing; and 
 a duct located between the diaphragm and the sound tube, 
 wherein an acoustic path through which sound is emitted is formed from the receiver to an end of the sound tube, the front housing or the rear housing includes a leakage hole, an inner end of the duct is connected to the acoustic path, and an outer end of the duct is connected to the leakage hole, 
 wherein the receiver further includes a protector coupled to the frame to protect the diaphragm and disposed to be in contact with the front housing, 
 wherein the duct is formed by a groove located on a rear surface of the front housing in contact with the protector. 
 
     
     
       5. The earphone of  claim 4 , wherein the leakage hole penetrates a front surface or a side surface of the front housing. 
     
     
       6. The earphone of  claim 4 , wherein:
 the leakage hole is formed in the rear housing; and 
 the protector includes a connection path formed by a groove on an outer surface and connected to the duct. 
 
     
     
       7. An earphone having a pressure equilibrium structure, the earphone comprising:
 a receiver including a frame, a magnetic circuit, a voice coil, and a diaphragm; 
 a front housing surrounding a front and a side surface of the receiver and including a sound tube; 
 a rear housing attached to a rear of the receiver and coupled to the front housing; 
 a duct located between the diaphragm and the sound tube; and 
 a plate for duct formation coupled to an inner surface of the front housing located at the front, 
 wherein an acoustic path through which sound is emitted is formed from the receiver to an end of the sound tube, the front housing or the rear housing includes a leakage hole, an inner end of the duct is connected to the acoustic path, and an outer end of the duct is connected to the leakage hole. 
 
     
     
       8. The earphone of  claim 7 , wherein the plate for duct formation includes a through-hole in the center thereof and includes a groove connected to the through-hole on a surface in contact with the front housing and forming a duct. 
     
     
       9. The earphone of  claim 7 , wherein the plate for duct formation includes a first plate including a through-hole and a second plate including a hole forming the duct. 
     
     
       10. The earphone of  claim 1 , wherein the duct has a spiral shape. 
     
     
       11. The earphone of  claim 4 , wherein the duct has a spiral shape. 
     
     
       12. The earphone of  claim 7 , wherein the duct has a spiral shape.